Thermal storage heating system



ug- 6, 1935. v z. DE FERRANTl 2,010,180

THERMAL STORAGE HEATING SYSTEM ALUM'INI'UM Fo'n..

Aug. 6, 1935. v. z. DE FERR/ANU ZS THERMAL STORAGE HEATING SYSTEM Filea March 25, 1952 2 sheets-sneei HEAT V .Z- Je ges/rami;

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Patented Aug. 6, 1935 PATENT OFFICE THERMAL 'STORAGE HEATING SYSTEM Vincent Ziani de Ferranti, Hollinwood, England, assigner to Ferl-anti Inc., New York, N. Y.

Application March 25 i932, Serial No. Sill In Greatritain May l, 193i 7 malins.

This invention relates to thermal storage heating systems of the type wherein a heat insulated mass of material of considerable thermal storage capacity is heatedgenerally electricallyand is employed to impart heat, e. g. to articles suchas dornestic cooking utensils or to airspaces tobeheated. The chief merit in such systems when electricity is employed as thesource of heat resides in the fact that the loading of the electric heating element may be comparatively low since it may be in operation to impart heat gradually to the heat insulated mass continuously or for prolonged periods, thus providing a load demand upon the electricity supply source of a most desirable nature in connection with which specially low energy supply rates are usually given.

In order that the benefits of thermal storage heating systems oi the above type may be fully realized it is necessary that unwanted heat losses from the mass be eliminated and it is the main ob ject of the present invention to provide arrangements wherein such losses may be greatly reduced.

Referring to the accompanying diagrammatic drawings- Figure 1 is a perspective view of one convenient construction with parts broken away.

Figure 2 is a cross sectional view oi a. detail.

Figure 3 is a vertical cross sectional view of the upper part thereof.

Figure i is a similar view of a modihed form.

Figure 5 is a front elevation partly in section of a modified construction.

Figure 5a is a similar view of a further modified construction.

Figure 6 is a section on the line A-A of Figure 5.

In carrying the invention into eiect according to one convenient example illustrated in Figure l as applied to an electric thermal storage system embodying a cylindrical block of iron a of considerable mass, say 1 hundredweight, there are provided, as a covering to the vertical sides and the horizontal base, shields of insulating material each constituted by a plurality or plates of metal l; spaced apartand highly polished on their surfaces adjacent the block or on both surfaces. Suitable metal for these plates is polished steel whch may be chromium plated.

'In the spaces between pairs of the metal plates b bright crinkled material is introduced which does not materially reduce the resistance of thermal conductivity oered by the air spaces, suitable material being Aalun'iinium foil c crinkled, e. g., by bending into wave form or otherwise so as to present series of reflecting surfaces to any heat radiated from the block which may have penetrated the preceding heat-reflecting layer and to prevent ready conduction o' heat through the spaces separating the plates h.

The top surface of the block a may be provided with a detachable cover d formed similarly to the shields described above. This cover may, if desired, be formed with a space beneath it in which utensils may be placed.

The bright plates b may be formed as individual cylinders surrounding the bleek, as indicated in Figure li, thus producing a series of metal casings of progressively increasing size one within another.

The cover which may be hinged if desired may he slotted or perforated to accommodate the handie oi a cooking utensil.

A heating element is represented at e and a base tripod at resting upon a sheet ci asbestos g which in turn is supported by a base h formed similarly to the shields.

According to the modication illustrated in Figure e a heat shutter device is provided which serves alternatively at will either to conduct heat from the top or the block a to the article or utensil to be heated or itself to form means for thoroughly heat-insulating said surface. This device comprises a plurality of inverted shallow dishes or plates highly polished on both upper and lower surfaces and of progressively increasing size, the edges of the dishes being adapted to enter the air space between pairs of metal plates b forming the side shields.

Light springs k support the outermost inverted dish, suitable heat insulating means m being applied as shown, thus resisting the conduction of heat to the springs. The middle and lower dish are each supported by chains n so that when no article is resting on the top of the uppermost dish air spaces are formed between adjacent pairs of dishes, as shown in Figure ll, whereas the placing of an article upon the upper dish causes the upper dish to be pressed down, so lowering the other dishes until all three are in mutual contact, the lowermost dish resting upon the upper surface of the heated block a.

According to this arrangement it will be appreciated that wasteful losses of heat due to failure to replace a removable heat-insulating cover are prevented, since the action of the device described is entirely automatic.

It is important that the dishes be formed of material through which the free conductivity oi heat may take place when they are in mutual contact sheet aluminium being convenient for this purpose.

It is also important that the polished surfaces should retain their polish notwithstanding the temperature to which they are subject, i. e. the maximum temperature of the block. Polished aluminium also comprises convenient material satisfying this requirement.

According to a modification illustrated in Figures 5 and 6 as applied to an oven with top hot plate surface, instead of providing springs for performing automatic action of the shutter device manually operated means such as a lever o in conjunction with suspension chains n and springs lc may be substituted, this modication being particularly advantageous as a ready vmeans of establishing or cutting off communication between the lower or side surface of the heated mass a and an oven space adjacent thereto, as shown.

Shutter devices may also be applied to control communication between a heated block and an air space such as a living room.

Shutter devices may be opened and closed automatically by a thermostat so as to control the heat conveyed to an oven or other space, thus maintaining the temperature at a predetermined level. One form of such arrangement is illustrated in Figure 5a, in which the lowermost shutter plate, y', is pivotecl at its centre to a link, q, whose lower end is pivoted to the free end of a thermostat device, p, secured atits remote end at r, to a xed part of the top surface of the oven space.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is:-

1. A thermal storage system having a heat insulated mass of considerable thermal storage capacity including a shield formed of at least one heat reflecting plate, andflexible means urging said plate to a spaced relation with an exposed face of said mass to act as a heat insulator but yieldable to return said plate into heat conductive contact with said mass over the whole of said exposed face whereby to permit of heat transmission from the mass through said shield at will.

2. A thermal storage system having a heat insulated mass of considerable thermal storage capacity including a shield formed of at least one heat reecting plate and yieldable means for normally holding said shield entirely out o f contact with an exposed face of said mass and permitting thermal contact of said shield with said face when the shield is actuated towards said face.

3. A thermal storage system having a heat insulated mass of considerable thermal storage capacity including a shield formed of at least one heat reecting plate and `means yieldable under the weight of an article to be heated, said means normally holding said shield entirely out of contact with an exposed face of the said mass and permitting thermal contact of said shield with said face when the shield is actuated towards said face.

4. A thermal storage system as claimed in claim 2 including means for actuating said yieldable means to bring said shield alternatively into contact with an exposed face of said mass or out of contact therewith.

5. A thermal storage system as claimed in claim 2 including means for actuating said yieldable means to bring said shield alternatively into contact with the whole of an exposed face of said mass and out of contact therewith.

6. A thermal storage system as claimed in claim 2 having manual means for actuating said yieldable means to control Vthe movements of said v shield. .f

7. A thermal storage system as claimed in claim 2 including thermostatic means for actuating said yieldable means to control the movements of said shield.

VINCENT ZIANI DE FERRANTI. 

